In recent years, stacked semiconductor memory devices having a large capacity where a number of semiconductor memories are stacked so that the device can be controlled as one semiconductor memory from the outside have been developed. In solid state drives (SSDs) using nonvolatile memories instead of a magnetic hard disc, for example, a number of flash memory chips of the same type are stacked so that the memory capacity can be increased.
FIG. 15 is a schematic diagram showing the structure of an SSD where eight memory packages 82 each having a stack of eight semiconductor memory chips 83 made of a 1 GB NAND flash memory are mounted on a substrate 81 so as to provide a 64 GB NAND flash memory that can be accessed from the outside. In this case a control chip 84 for controlling the operation of the 1 GB NAND flash memories is also mounted on the substrate 81.
The chips in such stacked semiconductor devices are connected and power is supplied through wires. However, it is becoming more and more difficult to connect these wires as the semiconductor devices increase in density and integration.
For this reason, the present inventors proposed communication between mounted stacks of chips and substrates through inductive coupling using coils formed of wires on the chips or wires on printed wiring boards in accordance with a technology for wireless connection between chips stacked in many layers of the above described stacked device or the layered printed wiring boards (see for example Patent Documents 1 to 6 and Non-Patent Documents 1 to 8). According to Patent Document 1, for example, a number of chips are stacked and data communication is made possible between chips through inductive coupling using coils for magnetic field communication.